AT&T says it has activated its 4G LTE network in areas of Los Angeles, Orange County and San Diego today, which means super speedy Internet access is coming for owners of mobile gadgets compatible with the new wireless network.

The launch comes a little more than a year after Verizon launched its 4G LTE network in the area.

AT&T’s network covers northern Orange County as far south as Mission Viejo while Verizon covers as far down as San Clemente.

Who shouldn’t be excited about this? AT&T customers who got a “4G” gadget for the holidays that wasn’t one of these:

HTC Vivid

Samsung Galaxy S II Skyrocket

HTC Jetstream tablet

Samsung Galaxy Tab 8.9

AT&T USBConnect Momentum 4G

AT&T Mobile Hotspot Elevate 4G

Those are the devices compatible with the new network, according to AT&T. But if you got a different 4G AT&T gadget you’re not going to see improvements made to this new LTE network.

Tip: Don’t buy 4G in 2012 unless it’s “LTE.”

Have one of these devices? Please share speed reports in the comments.

• Faster speeds. LTE technology is capable of delivering speeds faster than many other mobile broadband technologies. Customers can stream, download, upload and game faster than ever before.
• Faster response time. LTE technology offers lower latency, or the processing time it takes to move data through a network, such as how long it takes to start downloading a webpage or file once you’ve sent the request. Lower latency helps to improve services like mobile gaming, two-way video calling and telemedicine.
• More efficient use of spectrum. Wireless spectrum is a finite resource, and LTE uses spectrum more efficiently than other technologies, creating more space to carry data traffic and services and to deliver a better network experience.
• Cool new devices. AT&T offers several LTE-compatible devices, including new AT&T 4G LTE smartphones and tablets.

“We continue to see demand for mobile broadband skyrocket, and our 4G LTE network in Los Angeles responds to what customers want from their mobile experience — more, faster, on the best devices,” said Andy Shibley, vice president and general manager.